Authors : Panya Waewdee, Peerapol Sukon, Prapansak Chaveerach, Preeyaporn Surachon and Chaiyaporn Soikum
Abstract: Lactobacillus salivarius strain LP 4.2-2 (L. salivarius LP 4.2-2) isolated from chicken cecum can strongly inhibit Salmonella enteritidis (S. enteritidis) in vitro but little is known about its effect on prevention of this pathogen in live chickens. Therefore, the main objective of this study was to determine whether a single dose of L. salivarius LP 4.2-2 given at low or high dose by oral or cloacal route would prevent S. enteritidis infection in young broilers in addition, effects of the experimental treatments on total bacterial count in cecal contents, body weight, organ weight and intestinal length in chicks were determined. In this study, 240 of 1 day old male broiler chicks were randomly assigned to 6 groups of 40 chicks each. Chicks in each group were housed separately in a cage (size 1.5x1.5 m2). At 1 day of age, each group received none, 104 or 1010 (cfu/chick) of L. salivarius LP 4.2-2 by either oral or cloacal route. At 2 days of age, all chicks except those in one group (a negative control) were challenged orally with 104 (cfu/chick) of S. enteritidis. At 3 days of age, a half number of chicks in each group (n = 20/group) were randomly selected for the detection of S. enteritidis infection in cecal tonsils. Other parameters such as total bacterial count, body weight and intestinal length were also measured. The remaining chicks were allowed to grow until 9 days of age and then the procedures for measuring each parameter were done the same as those described above. The results showed that at 3 days of age, rates of S. enteritidis infection were lower in all groups administered with L. salivarius LP 4.2-2 than in a positive control group (13/20 or 65%-17/20 or 85% versus 19/20 or 95%). However, at 9 days of age, rates of S. enteritidis infection were high in all groups (95-100%), except in a negative control (0%). No significances were seen in total bacterial counts and in body weights between groups either at 3 or 9 days of age. After adjusted for body weight, weights of most internal organs in all groups and total lengths of intestine in most groups did not differ significantly. In conclusion, a single dose of L. salivarius cannot prevent S. enteritidis infection in all chicks but it can reduce rate of the infection in 3 days old chicks. However, the preventive effect is diminished over time.
Panya Waewdee, Peerapol Sukon, Prapansak Chaveerach, Preeyaporn Surachon and Chaiyaporn Soikum, 2012. Effect of a Single Dose of Lactobacillus salivarius on Prevention of Salmonella enteritidis Infection in Young Broilers. Journal of Animal and Veterinary Advances, 11: 955-961.